My buddy Steve has a Go camera. It's been dropped, run over, submerged and hit whilest cycling, skiing and kayaking. He mounts either on top of his helmet or in a chest harness. It's a durable little sucker. Video quality seems good to me. Chest-mounted, it works well, on top of your brain bucket it's pretty tall compared to the bullet form factor IMHO. But no overhanging rocks or trees have broken it, a couple enough to knock him off the bike.
"Why does the U.S. care which flag will be hoisted on a small piece of land thousands of miles away?" -- Ron Paul